Experiments in pigeon color-naming will be performed to develop a model system of coding, delimit pigeon hues, and to validate a general procedure for assessing perceptual capacities of lower organisms. Color-naming functions will be constructed from test wavelengths presented in a matching-to-sample paradigm. Properties of the color- naming functions will be assessed as a function of delayed matching observing-response requirements, number of test stimuli, and locations and spacing between training stimuli. These variables will bear upon the role of coding and generality of the color-naming function. A set of overlapping color-naming functions will be generated across the visible spectrum by successively changing wavelengths of training stimuli and then testing. These results will define the hues of the pigeon, and will be compared to the pigeon's hue discrimination function to reveal properties of a coding process and to compare processes of generalization and discrimination.